/*
*    Qizx/open 3.0 beta
*
* This code is the open-source version of Qizx.
* Copyright (C) 2004-2009 Axyana Software -- All rights reserved.
*
* The contents of this file are subject to the Mozilla Public License 
*  Version 1.1 (the "License"); you may not use this file except in 
*  compliance with the License. You may obtain a copy of the License at
*  http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
*  WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
*  for the specific language governing rights and limitations under the
*  License.
*
* The Initial Developer of the Original Code is Xavier Franc - Axyana Software.
*
*/
using System;
using DataModelException = System.Qizx.Api.DataModelException;
using EvaluationException = System.Qizx.Api.EvaluationException;
using NodeFilter = System.Qizx.Xdm.NodeFilter;
using EvalContext = System.Qizx.XQuery.EvalContext;
using ExprDisplay = System.Qizx.XQuery.ExprDisplay;
using Focus = System.Qizx.XQuery.Focus;
using XQItem = System.Qizx.XQuery.XQItem;
using XQValue = System.Qizx.XQuery.XQValue;
namespace System.Qizx.XQuery.Op
{
	
	/// <summary> class ChildStep:</summary>
	public class ChildStep:BasicStep
	{
		public override int Flags
		{
			get
			{
				return DOCUMENT_ORDER + WITHIN_SUBTREE + SAME_DEPTH;
			}
			
		}
		public ChildStep():base(null)
		{
		}
		
		public ChildStep(NodeFilter nodeTest):base(nodeTest)
		{
		}
		
		public override void  Dump(ExprDisplay d)
		{
			d.header(this);
			d.property("nodeTest", nodeTest == null?null:nodeTest.ToString());
		}
		
		public override XQValue eval(Focus focus, EvalContext context, XQValue recycled)
		{
			checkFocus(focus, context);
			XQItem currentItem = focus.currentItem();
			if (!currentItem.IsNode)
				context.error("XPTY0020", this, "context item is a not a Node");
			try
			{
				return currentItem.GetBasicNode().GetChildren(nodeTest);
			}
			catch (DataModelException e)
			{
				return dmError(context, e);
			}
		}
	}
}